TEST: Test that keyrings of the same name can be linked together [RHBZ 1071346]

Test that keyrings of the same name can be linked together.  This is a check
for:

	https://bugzilla.redhat.com/show_bug.cgi?id=1071346

Signed-off-by: David Howells <dhowells@redhat.com>
TEST: Can't do the bz1031154 test before 3.13-rc1

Can't do the bz1031154 test before 3.13-rc1 so skip the test if the kernel is
too old.  The big_key facility was backported to the 3.10 kernel used by
RHEL-7 so permit the test there.

Signed-off-by: David Howells <dhowells@redhat.com>
TEST: Display the name of the test we're about to run

Display the name of the test we're about to run to make it easier to work out
which test went wrong.

Signed-off-by: David Howells <dhowells@redhat.com>
TEST: Don't use "%..." key search commands generally

Don't use "%..." key search commands generally in the testsuite so that more
of it can be run on platforms for which the keyutils package installed doesn't
support this feature.

Signed-off-by: David Howells <dhowells@redhat.com>
TEST: keyctl show only takes an argument from 1.5.4 onwards

keyctl show only takes an argument from 1.5.4 onwards, so it cannot be tested
for prior to that.

Signed-off-by: David Howells <dhowells@redhat.com>